Empire Builder (N) - Derailments

[DMJ-Oregon]

Looking for ideas - help!  Received an Empire Builder set as a Christmas gift - my first train.  Built a layout modeled after p.21 (Bachman Getting Started - Building Your Layout) effectively 3' x 4'.  I have track laid on 2" foam covered in Bachmann Grass Mat.  Very frustrated by derailments of the loco.  I have added a bridge and an auto RR crossing in my layout.  I've examined the track again and again at the connections and believe they are pretty smooth.  Loco seems to hesitate at the bridge and RR crossing, but the derailments generally happen at the turnouts.  I'm lucky if I can get two complete circuits before off the track, running just the loco without freight cars.  My next move is to take out the bridge and RR crossing and see if performance improves.  Appreciate any ideas.